Sensing Light with Lys Technologies

In this episode, our guest is Christina Friis Blach, co-founder of Lys Technologies, about how light shapes our health, performance, and daily lives.

They explore how sunlight exposure and circadian rhythms influence sleep, hormones, and energy—and why modern indoor environments often disrupt this balance.

Christina shares how her company is helping bridge the gap between science and real life through wearable light technology and sunlight analysis tools.

☀️ About Lys Technologies

Lys Technologies develops wearable sensors that measure the light you’re actually exposed to throughout the day—close to the eye, where it matters biologically.

Unlike traditional light meters used in architecture, their technology focuses on human-centric lighting, tracking how light impacts:

•  Circadian rhythms and sleep 
•  Hormone regulation (melatonin, cortisol) 
•  Daily energy and performance 

Their tools are used globally across research, healthcare, workplace design, and even elite sports—helping drive better sunlight analysis, building design, and behavior change.

☀️ Key Takeaways

•  Light is a biological signal, not just for vision 
•  Modern lighting can disrupt circadian rhythms 
•  Wearable sensors enable real-world solar exposure tracking
•  Natural light is critical in real estate and building design
• Shadow mapping and sunlight analysis are shaping healthier spaces 

Sunlight Matters is a podcast exploring the role of the Sun in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and the way we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

Please do not forget to Like and Subscribe. 

Transcript

Christina Blach (00:00)
I was born with a heart disease.

You're not born healthy and you kind of have to to do it yourself, you know like make sure that you you live as long as possible So maybe that's why I have this drive for health so they found these other light-sensitive cells in the eye. sit right at the back of the retina and they take in light, but they have nothing to do with the visual system in our brain.

They're these time-givers to our hormone production

So that created like a real shift in how we need to think about how we illuminate our environment. Now we're getting daylight type of light when we turn light on when it's dark outside and that's confusing our circadian rhythm, right? It's confusing the melatonin production.

We needed to create some sort of tool that could help us identify what kind of light are we getting and how is it affecting us so like a feedback mechanism for humans to understand in real time

David Wallace (01:13)
Welcome to this episode of Sunlight Matters. I'm joined by Christina Black. co-founder of LIS Technologies based out of Copenhagen. So Christina, I wonder if you could introduce yourself and give us a bit of background to you and also LIS Technologies.

Christina Blach (01:33)
Yeah, sure. Hi, Dave, and thank you for having me today. ⁓ Yes, so, ⁓ yeah, my name is Christina. said that. Co-founded Lys Technologies 10 years almost ago now. So it's been a long journey. ⁓

I studied innovation design engineering. was sort of like a double master degree at Imperial and the Royal College of Art in London. So it's an interesting kind of invention, sort of core space for people to invent new technologies and innovation. ⁓ you get an MA in art from the Royal College of Art and then you get an MSc in science and engineering from Imperial. ⁓ And now it's kind of

Back then it was Dyson who was my provost and now he's kind of running that school at Imperial so that kind of makes sense that kind of space of engineering and design combining those two. it all started when I was a student there and we were doing a project with Intel at the time and they asked me to solve a problem in future urban environments and you kind of get this opportunity to just sit and like think about the problem you want to solve but it's very sort

of loose how you approach the idea. ⁓ And this was a solo project. Sometimes you collaborate with others. ⁓ And I was sitting there in our studio at night. We worked quite late. And we only had fluorescent light tubes in the ceilings. And I'm quite like a health freak, like a health freak. But I really love personal health, health, good food, all of these things. And yeah, I was born with a heart disease.

Some of my friends say maybe that's why.

You're not born healthy and you kind of have to to do it yourself, you know like make sure that you you live as long as possible and yeah, you live well So maybe that's why I have this drive for health

But ⁓ I'm never really this person who has headaches or anything but sitting in that fluorescent light like I started to have headaches and I didn't know much about light at the time, but I was like this is something like I'm I'm squinching like, you know, like this just it just feels unhealthy like I'm just I'm trying

to eat all these blueberries and doing all that stuff, but I'm just sitting here in these environments that feels like they're not good for me. And then I looked into this whole space and I got completely fascinated by the discoveries of Professor Russell Buster, Debre Scheen, all these amazing researchers in this space. I just couldn't believe how much we already back then, it was in 2015 or 2014, like how much we already back then knew about light's impact on health and

well-being but how little of that knowledge was actually with people on the street like people like me who was not part of that research circle and Yeah, just the discoveries of the rational ganglion cell I I get I don't know I think people who listening who's listening to this podcast might know about this but if not then we can go into it, but it was only in the 90s right and 1990s that discovery so it's fairly reasoned as well. So I was just yeah

I was just fascinated by that topic and I started out by developing these glasses with electrochromatic glasses actually. Like now I see you wear these orange tinted glasses, not blue blocking during the day, that's a good thing. yeah, so these electrochromatic glasses that could change color throughout the day for nurses working.

night shifts because I was kind of seeing that this was a big part like that was a group of people who really experienced a problem ⁓ with how we illuminate our world today and just because they're doing a work and they're taking care of everyone else but nobody's really taking care of them so I that's kind of how I started and yeah I don't know then I got into this female entrepreneurship program at Imperial ⁓

and started thinking, we made all these really amazing entrepreneurs, female entrepreneurs. There's a woman, she had sold her company to Tesco for two billion pounds, and there's just so many incredible women there. And I started thinking about, how can we create a product that can create more awareness around light's impact on health and wellbeing? ⁓ And that's when we came up with the first version of the sensor. So yeah, it's a long

story and yeah, but that's kind of how it's.

David Wallace (06:19)
Well, I mean, I love

it because it sort of sounds like, you know, the Genesis was based on your, what you felt as an individual. And it's been interesting talking to people on this podcast, how many have started with their own personal experiences and kind of gone from there. So it's fascinating. I mean, you talk about the ganglion cells. I mean, it might be worth just sort of because

because there will be a lot of people who don't know about that. So it might be worth just explaining what that is to start with.

Christina Blach (06:56)
Yeah.

So there's been a discovery in the 1990s by Russell Foster's group at Oxford. And they discovered that we have these third class retinal ganglion cells.

So like we know about rots and cones in the eye that takes in light and form vision in our brain, right? We've been knowing that for a long time. And then we kind of thought, okay, that's the sole function of the eye. Like that's the function of the eye we take in light, we see, we see. so they found.

these other light-sensitive cells in the eye. sit right at the back of the retina and they take in light, but they have nothing to do with the visual ⁓ system in our brain.

They are non-visual, as they call them, and they're these Zeitgebers, time-givers to our hormone production in the brain,

right? So all of a sudden, we now knew that light was not only there for us to see, but they were also there for us

to time ⁓ when we produce ⁓ melatonin, cortisol, like all these different important hormones that we need in the brain. therefore, light started to, we now know that light is actually a timing mechanism for us as humans. And we only illuminate our environments after the visual aspect, right? ⁓ So that created like a real shift in how we need to think about how we illuminate our environment.

 obviously it's not been so much of a problem beforehand. I grew up with the incandescent light bulb right when I was a kid and we had much more full spectrum, it was warmer but now with the energy like energy saving light bulbs and LEDs

like 24/7 kind of world screens, et cetera. Like we are getting spotlights in the bathroom, you know, we are kind of getting light at all times and it's not necessarily the right light that we're getting because with the incandescent light bulb, I think, yeah, that, you know, it was warm light. So when we turned it on, it was dark outside, but then at least we were getting warm light. But now we're getting daylight type of light when we turn light on when it's dark outside.

and that's confusing our circadian rhythm, right? It's confusing the melatonin production.

And I also remember it from being a student sitting in these lecture halls that were completely dark. I couldn't keep myself awake, right? Because you're not meant to be in darkness. ⁓ And even like the trend of fitness centers today being underground with purple light and, you know, like how we illuminate our offices, like all these co-working spaces that are dark and

with kind of home light, not daylight, right? So it's confusing. ⁓

David Wallace (09:53)
I mean,

we've been lucky enough to talk to Professor Glenn Jeffery on the podcast. What's so fascinating about that is it's not just the impact on eyes and circadian health, but it's also on metabolism that we're now seeing this as well. And I guess, when I think about where you... I'm so sorry?

Christina Blach (09:59)
Yeah.

Yeah? Yes.

mitochondria.

Yeah, the mitochondria system and he's looking into right through the skin and everything. Yeah, it's just, yeah.

David Wallace (10:28)
Absolutely. I mean, they've, there's sort of more and more coming out, which kind of shows our relationship, this close relationship of our bodies to life, which I guess when you stand back and look at it makes so much sense. And, you know, I guess what's surprising is you talk about like the 1990s, finding out about

the ganglion cells in the eyes being able to kind of set what happens from a kind of circadian point of view, but also, you know, now this sort of metabolic kind of discoveries. I mean, it's incredible that, you know, it's only just happening now. But what I'm fascinated about is the fact that you identified this potential issue and then you created these sensors essentially so that there would be information

that other people could use in order to kind of develop research. So I just wondered how you kind of arrived at that as an idea for a business and a sort of product.

Christina Blach (11:36)
Yeah, so I think there's several things. ⁓ When we talk about health, like going back to health, I felt like there was a lot of knowledge, as we said, what you eat, exercise, maybe air quality, yeah, like water, all of these things, but light was not really on the radar, like in the discussion at all. And actually when I started, some people were like, are you talking about crystals here? know, like was 10 years ago, it's still kind of a new,

⁓ area so

it felt a bit fluffy, I think, for many people. ⁓ But yeah, how I arrived at it. ⁓ So I it became apparent to me that maybe another part of this as well, I guess it's like vitamin pills as well. I mean, when you burn yourself, you feel the thermal reactors, like you feel the pain straight away. Whereas like when you get the wrong type of light,  you might not feel the pain straight away.  Or you might place that pain in a different

bucket like if you get ahead and you might just take a paracetamol or something like this you're not thinking okay maybe it's because I'm sitting in this horrible light all day and so I felt like we needed to create is some sort of tool that could help us identify what kind of light are we getting and how it is how is it affecting us so like a feedback mechanism for humans to understand you know in real time

and over time ⁓ how does light actually impact my health and well-being and and we launched a

Kickstarter back then. That's kind of a crowdfunding platform where you go out there and you tell people about a product that you're building and then you hope people want to buy it and back it. And when we look at that list, it was just incredible who bought the same service like big multinationals, like people working at Apple, Dyson, Amazon. Like it was just and then it was all these researchers from different universities across the world. And I was like, wow, OK, this.

something to this space that's really interesting. And that's how we also managed to investors on board, right? Because they saw, okay, and we only have private investors, but we needed some funding and like building technology is expensive. So ⁓ they could see that we also got all these people who were interested in actually after the Kickstarter, I just had conversations like you and I are having with all these, sorry.

with all these interesting people working from all over the world on really interesting projects and it just like I think there's this

What's interesting to this whole idea is that the timing is difficult. I think timing is always difficult, But I think now the time is more focused on light, but still not on the level as food, right? So the work that you are doing, the work that I'm doing is really important because as you say, we now know that light is really important. Like without light, we would not have

living organisms on this planet. So it is fundamental to, maybe so fundamental that we easily neglect it, you know? ⁓ But now with all that knowledge, we know how important it is for humans. there's definitely a lot of people looking into this space. And what became sort of the main use case of the sensor was in research. And I think that also says something about the timing, right? Like the research space was just growing and like,

We

have people using the sensors in over 55 different countries. And so from Thailand to Saudi Arabia to Denmark to the UK, US, there's this research done with light. it's in all sorts of different areas. could be in care homes, in hospitals, with children with myopia. Looking into light's impact on health and well-being.

underlines the fact that we're still learning about life's impact on health and well-being. We know a lot, but we're still learning and that's kind of what the sensor was supporting in a way, it always still is.

David Wallace (16:03)
And the sensors themselves, I mean, can you explain how they work and what they're able to measure?

David James Vaughan Wallace (16:13)


Christina Blach (16:36)
Yeah, so at the time, what was kind of the standard was to use a spectrometer that you put on the head of a participant in a research study, like in a very controlled study that could be used in an office and school environment and stuff like that. So I was like, okay, we need to know what kind of light people are actually getting in their real actual lives as they go around. And so we saw this need to build a wearable. ⁓

about that time where know Fitbits and all of these other wearables were very...

like starting to appear and become popular. So we said, okay, wearable, needs to be something that's fairly close to the eyes because we're trying to mimic the retinal ganglion cells. But yet again, it can't be like glasses or something in the middle, like people will just not wear it. Like we did a lot of design experiments, maybe back to you and I, talked about your background and user experience and your QI. And yeah, so we did a lot of that work on how do we actually make sure that people wear these?

devices and how do we make sure that they're not intrusive and uncomfortable to wear in a supermarket or something like this. ⁓ I think still when you're wearing it, it can become a conversation startup, but we saw that as a contribution to sharing the knowledge around light as well. obviously it shouldn't be so that it kind of interrupted the studies. And so we saw this need for building fairly small product. And when you build a product like that,

that there's a lot of sort of, you you adjust on different wearables. so like the size impacts the battery time and like how big of a battery you can have inside and how much storage you have and how much data accuracy and sampling rate and all of that. So a lot of the work was in sort of my space, which I enjoy, which is this kind of product development type of work where you have sort of, you have

you want to build a product and you want to get as close as possible to something that you think ⁓ makes a very sort of reliable. yeah, there's always we also wanted to create something that was not too expensive and affordable to because again, the other tools that were there at the time, they were in the thousands of dollars. So ⁓ if we wanted to start making research which allowed for bigger groups of participants

then we needed to get a product like that down in price. yeah, again, so there's like design, price, function, all of that working in that space to get to a device that ⁓ is sort of hitting the spot. And of course it can't hit.

the with all sorts of research because then there's something very specific you need to look into. then now last year we launched, so we started with the RGB sensor, which at the time was something we could get at that size and price ⁓ and allowed us to get a concept of light. But now we just launched with an 11 channel sensor as well. So it becomes something that is closer to a spectrometer.

want to say that we don't, we're not aiming to be a spectrometer because that's not what you need when you start talking about human health. But then, yeah, a lot of other really interesting subjects comes up when you start looking into this space. I don't know how much is relevant for this podcast, but I'm really happy to share. But so, so, so then you start talking about what is it then we, when we get the data, what is it then we refer to? Because the CIE tools were very much like this kind of light is this type of light.

But when you talk about light that a human is exposed to then it's maybe some daylight There's a bit of artificial light coming in. There's maybe some light from a screen. It's much more like a light scenario So that's also some of the things we're discussing a lot with researchers today is like how do we make a library of scenarios that humans are actually exposed to because a lot of people are so used to think about lux meters and spectrometers that are used in you know other fields like architecture and

⁓ photography and stuff like that. But that's not really what we want to get to here. now in this space, we're really talking about melanopic EDI as the main sort of it's not lux, it's melanopic EDI because we're talking about what the eye is reading, right? The amount of light, the color, et cetera, that goes into our brain. That's what we want to replicate if you see what I mean. So we came from a starting point.

David Wallace (21:25)
Yeah, no, no, mean, it's great to make that

distinction. So can you just sort of explain a bit more about that? Because I think you're totally right. Like when you think about sources of light, don't, you know, I'm surrounded at this moment by multiple sources of light. So, you know, I think it's really important to make the distinction.

Christina Blach (21:43)
Yeah.

Yeah, so I think when we started, we were kind of looking at products that were spectrometers, lux meters, like highly specialized tools that are also used in this kind of light research, but that you use in very controlled environments. And they were not really talking about what the human eye was reading, but they're useful for researchers because they give you a very exact idea. You can kind of be very exact, but then again, as you say,

as you stated just before, we're never in these environments in the real world where we're not in a sphere with one source. That almost never happened. And there was another thing that we saw with our first sensor, the V1, the button V1 we made, ⁓ that it had some challenges in monochromatic light. And we were like, well, but that's okay because humans are almost never in monochromatic light.

never happened, right? Like maybe at a disco later at night and like that monochromatic light is just hitting you right in the eye, but like it was not useful for our use case, But that was kind of with the research that we were working with, they were like, but it's really failing in this area. And I'm like, okay, but maybe that's fine. So it's kind of understanding constantly, what is the use case of our product? And we should not compare with existing products, because that's not what we're trying to achieve here, if you see what I mean.

And it's ongoing work, yeah.

David Wallace (23:17)
But I

No, do carry on because I think the field is sort of expanding, as you say. And I think what's interesting is how quickly people are sort of moving away from light as measured in terms of lux. It's now more about photons and where those photons are coming from.

I think which is really interesting because going back to what Glenn Jeffery and other researchers are looking at, it's like the full impact of light on us and the environment around us. And so I think it's kind of interesting how you're sort of qualifying what you're measuring.

Christina Blach (24:01)
Yes.

David Wallace (24:14)
So I mean, can you just talk about some of the use cases of your technology as well? So I know there's a lot of kind of research, but you've also published a paper which I thought was fascinating ⁓ on care homes as well. So I was kind of interested to kind of get your perspective on, as I say, the use cases that you've got.

Christina Blach (24:38)
Yeah, so there's, ⁓ as I said, like the sensor is used in many different use cases, but I can certainly give some examples. there's, yeah, there's, so we haven't published papers as a company, but people publish papers with our devices, right? ⁓ But there's been done work in care homes where they're looking into how the light impacts, you know, the elderly, the recovery, this ⁓ office environments where they're looking ⁓ at how the light

impacts the workers. did ⁓ one funny project that we did with Hawkins Browns in London where they, that's an architect studio and they made all their ⁓ workers wear the sensor and they realized that actually in summertime ⁓ the people who were sitting in the north side, like north facing part of the building were getting more light than the south facing because they were taking the blinds down because the light was too

too

strong so they couldn't really see the screens. So it's also interesting how the sensors kind of started to give these insights into how we actually built environments and how we start to be in these environments as well. And I think that's also the important part of it being wearable because you can also get sensors that you put into buildings, but they're not understanding the humans, they're just understanding the buildings. And I think that was one of the premises that I looked into right at the beginning.

Like how do we make sure that the buildings adapt to us as humans and not the other way around us? Adapting to the buildings and then that causing health problems to us, right? Like it should be the other way around and so so we also been doing a There's been like this academic research area where it's like highly scientific then there's Then there's areas where it's like in-house research. So we did some work with them edge technologies They built some of the most sort of sustainable buildings

in the world and now they're starting to talk about, okay, we want to have the healthiest buildings of the world. So we compare, we put sensors onto their employees and then we compare different sites, different types of buildings and then we started building two types of apps. So we have one app which is like a research app for scientific research where you do not want the test participants to see any data because you don't want

them to be biased. You just want them to be able to see, okay, the data has been synced to the cloud. Like it's possible for, like everything is working as it should. ⁓ But then we also have another app, which is maybe a bit more similar to what Fitbit app or something like this, where there's some data available to the participants. And this type of scenario is more for behavior change, which I think is really important as well. ⁓ And we gave the

those kind of apps to the participants in the ed buildings. And actually they started to change, you know, where they sit in the canteen, if it's co-working, where do I sit closer to a window? ⁓ Because with the sensor as well in real time, you can see how much light there is where you sit and where you move to. ⁓ People are saying they were starting to like walk a bit more in the evening, in the morning, for example, to go take the next tube, you know,

just to get some daylight and we tried to make these goals that people could get more light in the morning and make the most of natural light when it's there, right? ⁓ So there's these different use cases that are like, we like to say like we're here to sort of create, collect data that can help us advance in the field, but we're also here to help, you know, create behavior change, put some of the responsibility back on people on the

so to speak. ⁓ So they need to change the way that they live their lives as well and then with the data and then finally hopefully also to impact how we build our buildings today and how we illuminate our environments. So these are kind of the three steps in how we see the sensor is useful.

David Wallace (28:58)
Fantastic, fantastic. I think, I mean, you're kind of alluding to something which I think is interesting, which is ⁓ essentially using kind of the data, in line with other data sources as well. know, one of the reasons to kind of mention this is ⁓ my daughter's boyfriend, he's a Muay Thai fighter, and he was actually on the podcast as well.

Christina Blach (29:27)
Cool.

David Wallace (29:28)
I was saying, you need to think about life based on the kind of research I'd been doing.

Christina Blach (29:33)
Yeah.

David Wallace (29:33)
as

part of your training regime. And to begin with, he was like, what are you talking about? He was like, you just sound like you're in complete cloud cuckoo land. And I said, well, give it a go. And then I actually connected in with somebody had been on the podcast who, you know, she had actually had a lot of kind of background from a science point of view. And that's what he needed is, is a bit more kind of scientific.

Christina Blach (29:38)
Yeah, exactly.

David Wallace (30:01)
of a scientific foundation in terms of the stuff. Anyway, he's then sort of a kind of much more light-based regime and it's transformed his training. I mean, he looks so much better. He won his fight, did a fight on Saturday, he won that fight. But, you know, it's just like transformed him in many ways. And it's really interesting to me that ⁓ alongside kind of light,

Christina Blach (30:15)
Yeah.

David Wallace (30:31)
I mean, it would have been great if he could actually measure his light. But he's using things like Fitbits to kind of get all the information that they need. having light and kind of that health side of things kind of measured together, I think is really interesting.

Christina Blach (30:38)
Yeah.

Yeah, we also did like talking about use cases. We did some work with the English Institute of Sport in particular around the Tokyo Olympic Games and they were wearing the sensors to kind of understand. Yeah, also when they were just in the UK, understanding how the light was affecting them. And like don't quote me now we're on a podcast, but I think there's some studies showing that it's easier to win the medal in the afternoon, but also depending on your corner. And maybe that's also something that's

to talk about here but anyways they were using the sensors when they were traveling from the UK to Tokyo and then understanding how they could reduce jet lag all of that that impacts your performances and training ⁓ but yeah I think chronotypes are definitely something that I introduced into our app as well which is just so interesting and I don't know how much

your son-in-law is looking into that. from understanding your personal chronotype, now you said that your chronotype has kind of shifted after you had children. And we know that, yeah, that that's the case, right? That typically we see that young kids, young babies, young kids, are like early birds and then you become a bit later and then you become earlier again as you ⁓ get older. But there's also something that's kind of genetic.

David Wallace (32:00)
Yes, yeah, yeah,

Christina Blach (32:21)
it

disposed like where it's you know, are you a late night owl or you are early bird and I think that that whole space is just mixed with light is is so interesting and like understandings now we have Till Runenberg on our advisory board as well and he did the Munich Chronotype questionnaire in the MCT queue and understanding your own chronotype understanding how what is the optimal time for you to go to bed to

wake up, what is the optimal time for you to eat to get the right nutrition? You know, it's similar to when you drugs from the from your GP and they say take this in the morning, take it like there's a reason for that. That's because we have this circadian rhythm. Like you need to, you know, understand what you take in at certain times and the whole timing mechanism goes back to what kind of light we're getting. Right. ⁓ But also optimal time for workout, optimal time for cognitive heavy performance.

start talking about what light do we need to actually perform the best at work, at what time is the best and how can we manipulate that if we need to with light, for example, in dark times of the year. All of that, think, is just such a fascinating space. And I think with chronotypes, we can start becoming much more personalized in the way that we kind of approach personal health and light in many ways. And so that's definitely something we're looking into.

and like also ⁓ doing with some of the clients that we're working with. And I think it's also sleep is a huge topic and obviously that's also super tightly knit with blight, right? And we did a lot of work with extra health insurance where we said, yeah, but you can have these sleep trackers and you can measure sleep, but actually that's informative, but it's not that.

useful for changing behavior because it's not like you can say okay last night I had three hours of REM sleep in a Ruger but this time like I'm not gonna do that I'm gonna set an alarm clock not to do that next night you know like you kind of need to look into what are the influencing factors on my sleep and then understanding how you can change that and light is the main influencing factor on your sleep so starting to measure what kind of light you're getting is really interesting too and then actually you should maybe just feel how do you feel how do

look as you say how do you perform rather than measuring sleep because in the end of the day you know it's it's much more about how how you how you feel and how you perform

David Wallace (35:02)
I get it fascinating. I mean, I really, I really like sort of that, that whole idea of kind of understanding this, but from an individual point of view. you know, one of the things, and I've talked about this, that I've tried to do and I'm starting to do is to get up with the sunrise. ⁓

Christina Blach (35:14)
Yeah.

David Wallace (35:23)
You know, so we've just had the clocks change, obviously. So, you know, it's an hour later, but, ⁓ you know, I've been doing a good job of actually kind of following the arc of the sunrise so far. And I'm intending to do it for the rest of the summer, which you can just about do in the UK, I think, without it sort of becoming too early. But it's made a massive difference to me, you know, just sort of in terms of how I feel, how I sleep.

I guess, I mean, I'm a bit of a data nerd as well. So I'd love to understand what that looks like from a kind of light point of view. ⁓ So, you know, again, lining all of these things up, I think is really interesting. So, I mean, just on the chronotype, because I think that is a really is. So if you got kind of. ⁓

Christina Blach (35:57)
Yeah.

David Wallace (36:20)
product developments coming out around that or research? Where are you at with that?

Christina Blach (36:26)
So currently we have an app version of the chronotype questionnaire in our Lys track app. You can just download it for free on App Store and you can take the chronotype questionnaire and get a bit of information about what chronotype you are based on your answers. then, yeah, like optimal time for bed, optimal time for wake up for your chronotype and cognitive heavy performance and optimal time for exercise.

size and sport. So yeah, you can do that just for fun. There's other ways of understanding your chronotype as well. But right now, it's something that, from a science point of view, that is based on questionnaires. ⁓ And yeah, you can change your chronotype with light. And we know that from when we travel through time zones, et cetera. ⁓ But yeah, it's a fascinating area because I think they were doing

research on optimal time for chemotherapy based on coronatipes, optimal time for heart surgery. ⁓ All these things, timings of these different things is so interesting based on the individual. So we start personalizing all of these important ⁓ aspects of ⁓ health and wellbeing as well, ⁓ based on coronatipes, like optimal time for nutrition, medicine. And it's just a new world.

that's opening up, right? ⁓ It's slightly leaning towards biohacking as well, right? But we are already sort of hacking into our biology, like you talking about getting up with the sun. Like the idea about us being awake as much as in the winter, as much as we are in the summer is kind of silly, right? Because it's so dark in winter, we should be sleeping more in many in the Northern Hemisphere at least.

And then we use artificial light to kind of facilitate that. ⁓ That's also hacking into our biology in a kind of a wrongful way, right? But yeah, we could do it in the other way where we're a bit more mindful about what we are doing actually to our bodies and what we're trying to achieve here.

David Wallace (38:46)
No, I mean,

it's interesting because I, like I, this winter, I, because I get sad incredibly badly. mean, was born in the tropics. Yeah. I was born in the tropics. I was supposed to live under kind of, yeah, equatorial light, I think. But this year I was like, you know what, I'm just going to, instead of getting annoyed about sad, I'm just going to lean into it and I'm going to just relax, not relax, I'm just going to be

Christina Blach (38:53)
Yeah, most of us do.

Really fantastic.

Yeah.

Sad.

David Wallace (39:16)
just do what my God is

telling me to do. And actually, that really helps with the whole thing.

Christina Blach (39:22)
Yeah.

David Wallace (39:24)
So no, it's such an interesting topic. And then in terms of light and I mean, I guess an obvious question is, do you think people like Apple will start embedding kind of light meters into some of their technologies? I mean, I guess it's sort of more complex for them to be able to do that, but it's.

What we're seeing certainly is that there is suddenly so much more appreciation of light. So from a shadow map point of view, ⁓

You know, we have access now to information from some of the big property portals which show that people's preference is for well-lit houses to the point where, you know, a large percentage of people will choose.

a house based on what kind of light is coming in. So we can see this as a topic which is growing and growing. ⁓ I guess it then would make sense for some of the big tech companies to think about how they'd incorporate some of this thinking or technology as well.

Christina Blach (40:46)
I certainly changed my view on architecture. Like I remember walking around London and finding all these Victorian houses so beautiful. And then after all of this knowledge, I was like, I'm never going to live in a Victorian house because there's no light coming in, right? Like it's just interesting how you can change your perspective on so many things with that knowledge. ⁓ it's, yeah, it's like you can not go back when you know, right? And it's like, ⁓ so that's interesting you mentioned that. ⁓

David Wallace (41:01)
No.

Christina Blach (41:16)
But yeah, the big multinationals. So it has certainly been a thing for us that we got approached by all these companies. And sometimes I don't know if that's a blessing or not for a small company, because then you spend a lot of time and you like you're so small compared to them. But that's a different conversation, I guess. I don't know exactly what they're doing at Apple, but I know that ⁓ we've been working a bit with them on some workshopping and then

and they introduced the night shift, right? There was the flux on the computer and then they introduced their own night shift back then and they were definitely at that time looking into how can we, you know, look more into this space as part of the health space in Apple but I don't know much more about that and I guess, you know, that's highly confidential as well but we all what they're working on but I think 10 years, like, yeah,

David Wallace (41:51)
Yes.

Yeah, no, no.

Christina Blach (42:16)
It is really interesting how when I started, it was really like that experience you had with your son-in-law, like are you talking about crystals? What are you on about here? And now maybe there's a bit more focus on it, but it's still like, I think most people, they're scared of blue light and scared of screen light. Maybe that's not what the conversation should be about, right? Because we need blue light during the day to depress melatonin.

the that are maybe not so much the problem because they're relatively small sources of light, right? It's maybe more the disturbance of all the things that they make you think about or the kind of brainwashing of these screens. But then it's maybe more the horrible spotlights that people install in their bathrooms and when they brush their teeth and all of that. yeah, think light has come to an interesting point, as you also mentioned, where it's not just

and we're talking about it. Maybe that's not enough. the lighting industry, they were talking about human centric lighting being like a huge market, trillion dollar market by 2024. And let's just face it, it's not, that has not happened, right? And why? Yeah, we can talk about that. But ⁓ I think it's just interesting that now we're starting to talk, as you said, metabolism and mitochondria system. We all known about D vitamin production, like all these different areas of light and how it impacts our health and wellbeing.

and how important it is for sleep, like much more important than what you eat and exercise, right? Like I think, I think it's just gonna be interesting to see like.

How are we gonna really put focus on this? We should not keep preaching to the choir, right? We need to get out of that church and preach to the rest of the world. that's also why I'm thankful for you doing a podcast like this that's super important, right? We need to get out there with this knowledge that exists and hopefully with products that can kind of help people create value for people in the real world.

you

David Wallace (44:29)
Well,

look, mean, I'm super, thankful for people like you who have created technology that can be used to gather data. Like data is so important around all of this. We live in a world where I think there's so much subjectivity around topics and actually to be able to objectively measure and

draw conclusions is absolutely essential, which is, you so I think it's great because, know, your ability as a business to kind of help kind of academics and kind of broader communities understand.

sort of levels of light and then draw their own conclusions about the impacts of those lighting, think is fundamental. It sort of feels like a very exciting time to be in the field where the world has sort of suddenly woken up to it. ⁓

Christina Blach (45:28)
different.

Yeah.

David Wallace (45:33)
And certainly it's great because you've got people like ⁓ Huberman and his podcast and he's talking more and more about light as a foundational thing. And the more I think about it, you don't need all of this to then really think about light, actually life.

Christina Blach (45:41)
Yes.

is.

David Wallace (45:55)
this relationship that life has with light is so intrinsic that the fact we would be finally tuned to light shouldn't be a surprise to any of us, should it?

Christina Blach (46:07)
Exactly. Exactly. Yeah.

David Wallace (46:12)
Well, listen, thank you so much for joining. I really appreciate you coming on. It's been fascinating. ⁓ I'm going to actually buy one of your sensors, and I should have done it, but I'm going to buy one of your sensors. And ⁓ I'm kind of interested to marry the data with something like Shadow Map and what we see from a kind of modeling point of view.

Christina Blach (46:37)
Yes exactly.

David Wallace (46:39)
and sort of marrying those two things up because I think it's sort of, actually we're all part of a kind of this jigsaw puzzle, aren't we? And we're sort of slowly putting pieces together. And I think the more we kind of harmonize data and sources of data, the stronger the conclusions we reach are gonna be.

Christina Blach (47:00)
I agree, completely agree. Yeah, but thank you so much, Dave. I feel like we could talk for ages about this topic, but it's been a pleasure to be here in this space with you. Yeah, so thank you.

David Wallace (47:08)
Well.

my pleasure. I'm just going to press stop.

David James Vaughan Wallace (47:18)
Thanks for listening to Sunlight Matters, brought to you by Shadowmap where we explore how sunlight influences the way we build, design and live each day. If you like what you heard today, be sure to subscribe, follow and leave a review on your preferred streaming platform. You can also search Sunlight Matters on Google to find all our episodes, guest information and resources about sunlight analysis, solar exposure and the best home orientation for natural light.

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